We flew to Madrid to prove how difficult it is to find the crooks behind lotto junk mail. Our dossier included letters from Euro Millones, The International Lottery Board, Lottery Primitiva and the Loteria International de Europea.

They claimed to be based in Madrid's Calle Cordoba, Avd Juan Real, Plaza Juan Carlos, Carraca de Mayor and Calle Aroyo. None of these streets exists.

Only two of the lottery letters used real street names. One, cheekily, turned out to be the offices of the official Spanish Lottery, where the receptionist had a stack of leaflets to give to victims of this fraud.

The other was the International Lotto Commission, which boasted a head office at 54, Plaza de Colon. The Plaza exists, but number 54 doesn't.